Let-off



Dec. 1, 1936. v PAYNE 2,062,725

- LET-OFF Filed May 8, 1934 2 Sheets-Sheet l was cgnuehtor (9:50am UPo ne (lttorne u a Dec. 1, 1936.

o. v. PAYNE LET-OFF Filed May 8, 1934 2 Sheets-Sheet 2 H I F e r 3 e m? m wm wv Patented Dec. 1, 1936 UNITED STATES LET-OFF Oscar V. Payne, Leicester, Mass, assignor to Cromptpn & Knowles Loom Works, Worcester, Mass, a corporation of Massachusetts Application May 8, 1934, Serial No. 724,527,

6 Claims. (01. 139-109) This invention relates to improvements in letoifs for looms and it is the general object of the invention to provide means for increasing the rate of feed of the warp threads.

In my prior Patent No. 1,803,143 there is shown a let-off which has gone into extensive use and. having in its constructions a weight which tensions the warp threads through a worm and worm wheel. As the warp is consumed a support for the weight is moved forwardly together with the worm, worm wheel and worm actuating plunger, and when a predetermined point is reached a regularly acting feed arm or wing pushes the plunger. The plunger acts to rotate the worm in such a direction as to turn the Worm wheel and weight support backwardly. By this means the weight constantly stresses the warp threads without being wound up on a large drum or rising through a large distance and continuous forward movement of the warp is accompanied by an alternate forward and backward movement of the worm and weight support.

The plunger shown in my prior patent is moved inwardly by the feed arm every beat of the loom, but I have found in certain fabrics which use very coarse weft that the advance of the warp thread is so rapid as to require more frequent feeding than can be accomplished by the motion shown in said patent. It is accordingly an important object of my present invention to provide means for giving the plunger more frequent actuating motions and this result I accomplish as set forth specifically hereinafter by means of a toggle type of motion in which each backward and each forward motion of the lay effects a feeding motion of the plunger. A motion of this type can be readily adapted to a letoff shown in the previously mentioned patent, but it is not necessarily limited to motions as shown therein.

With these and other objects in viewwhich will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth in the claims.

In the accompanying drawings, wherein a convenient embodiment of my invention is set forth,

Fig. l is a side elevation of a loom having my invention applied thereto,

Fig. 2 is a detailed top plan view of one rear side of the loom taken in the direction of arrow 2, Fig. 1,

Fig. 3 is a detailed view partly in section of part of the structure shown in Fig. 1,

Fig. 4 is a horizontal section on line 44 of Fig. 3, and

Figs. 5, 6 and '7 are diagrammatic views showing the parts in different positions.

Referring. to the drawings, the loom frame [0 is provided at the rear thereof with a warp beam B supplying warp W. The lay L is driven back and forth in the usual manner by crank shaft IS. The gudgeons 20 of the warp beam pass through vertically adjustable supports 44, one of which is shown in Figs. 1 and 2, bolts 45 passing through the loom frame and the supports 44 to afford adjustment.

A worm wheel 36 is secured to the warp beam and is rotatable with the latter about the axis thereof, and meshes with aworm 50 keyed to a shaft 52. This shaft has rotatable thereon a collar 64 which has a ratchet tooth connection 66 with a second collar keyed to the shaft. The collar 64 is provided with gear teeth 18 which mesh with a rack l9 formed as a part of a plunger 16. The latter reciprocates in a housing 30 which forms part of the support for the worm wheel 36, and a light spring tends normally to hold the plunger outwardly. A stop II as shown in Fig. 4 limits outward movement under action of the spring.

When the plunger 16 is moved inwardly it turns the collar 64 in a clockwise direction, as viewed in Fig. 4, to turn the collar 60 through the ratchet connection 66, thus rotating the worm 50. The latter in turn gives a partial backward or reverse rotation to the worm wheel so that a segment 62 which supports a weighted cord C moves in a left hand direction as viewed in Fig.3.

As shown more particularly in Fig. 2 a feed arm or wing 84 is pivoted at to the support 44 and is adapted to rock in a fixed plane. When the segment 62 and the worm, together with the worm wheel and the plunger 16, are in their extreme left hand position the plunger is out of the path of the wing. 84 and the latter vibrates idly. As weaving continues the warp W moves forwardly and turns the beam and the plunger in a right hand direction as viewed in Figs. 1 and 3, ultimately bringing the plunger into the range of action of the wing 84, after which reverse feeding of the worm as already described will take place. The matter thus far described may be substantially the same as shown in my previously mentioned patent and of itself forms no part of my present invention.

In carrying my invention into efl'ect I provide means for giving the plunger 16 an increased number of reciprocations for each beat of the f. the plunger.

loom. The mechanism for accomplishing this result is set forth in Figs. 2 and 4, where it will be seen that the wing or feed arm 84 has pivoted thereto a link 90 which in turn is pivoted at 9| to a second link 92. The latter is pivoted as at 93 to a fixed extension 94 of the support 44. A rod 88 is pivoted as at 89 at its rear end to the link BZandWat its forward end ispivoted to a lever 14 which-in turn is connected to a second rod 15 attached pivotally at 95 to the lay sword 96.

-indicated in Fig. 6, the rod188 will pull the links until they are straightened, thereby swinging the wing or feed arm toward the plunger and moving thesame to give a feeding motion to the worm 59.

As the lay continues to its extreme forward posi- Jtion as indicatedin Fig. 7 the links'will move forwardly in away to retract the wing. As the lay starts backwardly theparts will again assume theposition shown .in Fig. 6 withthe links aligned and the wing giving the plunger another feeding action. When the lay reaches its extreme rearward position thelinks will be as indicated in Fig. 5.

It will 'be seen 'by .these motions that each sweep of the lay either backwardly or forwardly .zwill move the wing 84 into operative relation with .theplunger 16 to feed the warp. In other words, for each complete pick orcycle of the loom in- ;cluding a forward'and backward movement of ithezlay there will be two feeding movements of In this way the let-off is adapted for use with very coarse weft where the feeding of the warp mustbe rapid.

From the foregoing itwill-be seen that I have provided a very simple means for increasing the speed-at which warp'can be fed with a let-off motion, the mechanism preferably employing toggle members :which give the feeding: plunger 16 a .working'stroke twice for each beat of the loom.

Having thus described my invention it will be seen that changes and modifications maybe made therein by those skilled in the art without departing fromthe spirit and scope of the invention and I do not wish to be limited'to the details herein disclosed, but what I'claim is:

1. In a loom having a warp supply, a lay mov- "able backwardlyand forwardly'therein, a let-off including a yielding element to control feeding of the warp supply, actuating means to cause relative movement of the element with respect to the warp supply, andmeans defining a toggle joint operatively connected to the lay to give saidactuating means an operative movement In my prior patent I have shown an eccen.. tric on the crank shaft to oscillate the rod 88,

defining a toggle joint, andmechanism to cause said toggle joint to give the control named means an operative movement relatively to the weighted means each time the lay reaches its mid position between front and extreme positions regardless ofthe direction of movement of the lay.

3. In a loom having a warp supply, a lay movable backwardly and forwardly therein, a let-off to feed the warp supply, weighted means forming part of the let-ofi to tension and resist feeding of the warp and tending to move with'the warp as the latter feeds forwardly, control means to effect a relative backward movement of the weighted means with respect to the warp, a wing member to engage and actuate the control means, a pair of links constituting a toggle joint operatively connected to the wing member, and connections between one of the links and the lay to straighten said links and give the wing member an operative motion with respect to the meanseach time the lay moves between its front and back extreme positions.

4. In a loom, a lay movable back and forth, a warp beam, a worm wheel fixed thereto, a weighted casing pivotally mounted concentric with said worm wheel, a worm rotatably mounted in said casing and engaging said worm wheel, a toggle joint operated by the lay twice each time said lay has a back and forth motion to intermittently actuate said worm as the warp is unwound from said beam, said casing being relatively movable angularly in one direction by the unwinding movement of the warp beam, and said casing receiving a compensating relative angular movement in the oppositesdirection by the coactionof said worm and worm wheel, and a releasable 'clutch connection between said worm and said actuating means, whereby said worm'may be released for manual actuation.

5. The combination in a loom as set forth in claim 4, in which a gear is mounted co-axial with said worm, a clutch connection is provided between said gear and said Worm, and a rack operable-by the toggle joint engages said gear, said rack being movable longitudinally in one direction by said toggle joint to rotate said worm and gear.

6. The combination in a loom as set forth in claim 4, in which a gear is mounted co-axial with said worm, a clutch connection is provided between said gear and said worm, and a rack operable by the toggle joint engages said gear, said rack being movable longitudinally in one direction .by said toggle joint to rotate said gear and worm and being movable in the opposite direction by a spring.

OSCAR V. PAYNE. 

